闽江河口湿地土壤磷形态变化对盐度增加的响应及其影响因素  

Response of soil phosphorus forms to increased salinity in the Min River estuarine wetlands and its drivers

作　　者：倪冉旭 胡敏杰 钟懿 闫睿冰 吴辉 王景涛 刘春雅 廖浩宇 NI Ranxu;HU Minjie;ZHONG Yi;YAN Ruibing;WU Hui;WANG Jingtao;LIU Chunya;LIAO Haoyu(Key Laboratory of Humid Subtropical Eco-geographical Processes,Ministry of Education,School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,China;Fujian Minjiang Estuary Wetland Ecosystem National Observation and Research Station,National Forestry and Grassland Administration,Fuzhou 350215,China)

机构地区：[1]福建师范大学地理科学学院,湿润亚热带生态-地理过程教育部重点实验室,福州350117 [2]国家林业和草原局福建闽江河口湿地生态系统国家定位观测研究站,福州350215

出　　处：《生态学报》2024年第16期7140-7149,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金(42171102);福建省林业科技项目(2023FKJ14);中央财政林业科技推广示范项目(闽【2024】TG28号);福建省自然科学基金(2021J01177)。

摘　　要：以闽江河口湿地为研究对象,沿自然盐度梯度分别采集不同盐度区的短叶茳芏湿地(有植被)和光滩(无植被)土壤样品,对不同盐度条件下土壤理化性质、植物生物量及土壤磷形态等进行研究,以评估盐度增加对湿地土壤磷形态变化的影响及其调控因子。结果表明:①不同盐度条件下,土壤全磷和各形态磷含量大体表现为短叶茳芏湿地高于无植被的光滩,尤其在淡水条件下最为显著。总体上,随盐度增加,土壤全磷和有机磷含量逐渐减低,无机磷和氢氧化钠磷含量表现为先降低后增加,而盐酸磷含量则逐渐增加。无机磷是闽江河口不同盐度湿地土壤全磷的主要赋存形态,分别占全磷的74%、77%和83%,占比随盐度增加而增大。②不同植被条件下,短叶茳芏湿地土壤全碳、全氮含量和氮磷比均显著高于光滩土壤(P<0.05)。不同盐度条件下,淡水区土壤全碳、全氮含量和碳氮比均显著高于咸水湿地,并且高盐区大于中盐区(P<0.05)。③地上和地下植物生物量沿盐度梯度呈现明显不同的趋势,地上生物量表现为随盐度增加而增大,地下生物量在淡水区高于咸水区,尤其是显著高于中等盐度区。④相关分析显示,盐度及其关联的地上/地下生物量、全碳、全氮和有机质含量等的变化共同调控了土壤磷形态和有效性的变化。研究表明,滨海河口湿地盐度的增加通过改变土壤有机质含量和地上/地下植物生物量,调控了土壤磷的形态和转化,进而影响湿地生态系统的养分循环和化学计量平衡。In the Min River estuarine wetlands,we investigated the changes in soil physicochemical properties,plant biomass,and soil phosphorus(P)forms in Cyperus malaccensis wetlands and bare mudflats under different salinity conditions,to assess the impact of the increased salinity on the changes in soil P forms and their regulating factors.The results showed that:(1)Across diverse salinity conditions,soil total P and various P forms consistently showed higher levels in C.malaccensis wetlands than in bare mudflats,with a notable significance under freshwater conditions.Overall,as salinity increased,soil total P and organic P contents gradually decreased,while inorganic P and NaOH-P contents initially decreased then increased,and HCl-P gradually increased.Inorganic P was identified as the primary form of soil total P in the Min River estuarine wetlands,accounting for 74%,77%,and 83%of total P,with the proportion increasing with salinity.(2)Under varying vegetation conditions,soil total carbon(C),total nitrogen(N),and N:P ratios in C.malaccensis wetlands surpassed those in bare mudflat soils(P<0.05).Furthermore,in different salinity conditions,soil total C,total N,and C:N ratios in freshwater sites were notably higher than in saltwater wetlands,with high salinity areas exceeding moderate(P<0.05).(3)Plant aboveground and belowground biomass exhibited distinct trends along the salinity gradient.Aboveground biomass increased with rising salinity,while belowground biomass was more substantial in freshwater sites than in saltwater,particularly significantly higher in moderately salinity.(4)Correlation analysis indicated that changes in salinity and its associated aboveground/belowground biomass,total C,total N,and organic matter collectively regulated the variations in soil P forms and availability.The study suggests that increasing salinity in coastal estuarine wetlands alters soil organic matter content and aboveground/belowground biomass,thereby influencing the forms and transformation of soil P.This,in turn,has implications

关 键 词：磷形态 有机质 生物量 自然盐度梯度 闽江河口湿地 

分 类 号：X171.1[环境科学与工程—环境科学] S153.6[农业科学—土壤学]